A line movement chart should tell readers what changed and when. Suppose a basketball team opens at -2.5, moves to -3 before tipoff, and then becomes more expensive at -3. A chart that records only the spread misses the price change. A chart that records only the price can hide the fact that the underlying bet changed.
Developers can start with PreciseAPI’s independent DraftKings odds API guide, which describes the sportsbook’s main lines, alternate markets, player props, and futures in a normalized feed. It also explains how DraftKings Sportsbook and DraftKings Pick6 appear as separate sources, a distinction that matters when a product covers both.
Record the line and its price together
Consider a hypothetical spread that opens at -2.5 at -110. Later, the same team is -3 at -105. By the afternoon, it remains -3 but costs -115. These observations show two different changes. The move from -2.5 to -3 changes how the bet settles at a three-point margin. The move from -105 to -115 changes the payout on the same -3 selection.
Store the line, price, side, timestamp, and market period on each observation. A chart can then show the spread as a step series and display the price when the reader selects a point. If the product offers a dedicated price chart for -3, it can filter to that threshold and keep earlier -2.5 quotes out of the series.
Alternates need a separate treatment. If -2.5 remains available after -3 becomes the main line, both numbers can exist at the same time. Tagging the main line and alternate offers allows the chart to follow the primary spread without erasing the alternate prices.
Define the open and close before building reports
An opening price may mean the first quote your feed recorded for the book. If your coverage started after the market was posted, label it as the first observed price. A closing quote should have an equally clear definition, such as the last eligible pregame price before the event began.
PreciseAPI documents timestamped history for supported main full-game markets. A product that also needs long-term history for alternate lines or individual props should check coverage for those markets and plan its own snapshots where necessary.
Rescheduled games deserve extra care. If the start time changes, an application should preserve the original observations and apply its closing rule against the actual event cutoff. Otherwise, a report can accidentally mix pregame quotes with prices recorded after play began.
Compare closing prices on the same selection
A ticket taken at +115 that closes at +105 received a better payout than the closing quote if the market still describes the same outcome. In decimal odds, that price comparison is 2.15 divided by 2.05, minus one, or about 4.9%. The example measures the price difference against a single raw closing quote. A separate no-vig comparison would need a fair closing probability.
Threshold changes require more context. Comparing -2.5 at opening with -3.5 at closing tells you the market moved a point. A price-only comparison between those records can obscure the fact that a three-point win settles them differently. Reports can show the movement in points and calculate price-based closing-line value only where the original selection has a matching closing quote.
Keep DraftKings Sportsbook and Pick6 separate
DraftKings Sportsbook offers fixed-odds markets, while Pick6 uses player selections whose payouts depend on the entry. PreciseAPI exposes the sportsbook as draftkings and Pick6 as dk_pick6. Shared event and player identifiers allow a product to show both sources in the same player view while keeping their offers separate.
For Pick6, a movement history can track changes to the posted projection or offer details. For the sportsbook, it can track the threshold and quoted price for each side. If both products appear on one page, separate labels and histories help the reader tell which market moved.
A good first chart can cover one league’s main spreads and totals. Plot the observed timestamps, display the exact quote on inspection, and show gaps where records are missing. Once the underlying history is consistent, the same observations can support matchup previews, line movement alerts, and closing-price reports.
